Association between inflammation biomarkers, anatomic extent of deep venous thrombosis, and venous symptoms after deep venous thrombosis

Exploration on the effect of anserine on the alleviation of DVT and its molecular mechanism

Background

This study aimed to explore the regulatory effect of anserine on HUVEC cell injury and thrombosis in deep venous thrombosis (DVT) rats, and to elucidate the underlying molecular mechanisms.

Methods

Non-targeted metabolomics data analyses were conducted using an ultra-performance liquid chromatography system Vanquish UHPLC and mass spectrometer to detect plasma metabolism profiles. The transcriptome sequencing and gene intervention experiments were performed to verify the regulatory effect. Further in vivo and in vitro experiments were performed. Enzyme-linked immunosorbent assay was used to detect the levels of P-selectin, E-selectin, and vWF, hematoxylin-eosin (HE) staining was performed to observe thrombotic and inflammatory cell infiltration, flow cytometry and TUNEL assays were performed to detect apoptosis, and qPCR and WB assays were conducted to determine the gene and protein expression.

Results

Anserine alleviated HUVECs injury, reduced adhesion molecule expression, and inflammation. It decreased P-selectin, E-selectin, vWF, THBD, TFPI levels, and apoptosis while promoting NOS3, ET-1, and NO release in HUVECs. In DVT rats, anserine reduced P-selectin, E-selectin, vWF, thrombosis, cell infiltration, apoptosis, and promoted NO release. Transcriptome sequencing and gene intervention confirmed anserine's regulation of the PI3K-Akt pathway and coagulation via MYB. CARNMT1, a regulatory enzyme for anserine metabolism, increased anserine content, inhibiting coagulation, thrombosis, cell infiltration, and promoting NO release in rats.

Conclusion

This study confirmed anserine could alleviate DVT by improving the inflammatory response, inhibiting blood agglutination, and promoting vasodilation, providing new potential therapeutic targets, important scientific evidence for the development of DVT management, and new clues for an in-depth understanding of its molecular mechanisms.

Systemic immune-inflammation index as a novel hematological marker for predicting the recurrence of deep venous thrombosis

OBJECTIVE

To determine whether there was a possible predictive relationship between systemic immune-inflammation index (SII) and recurrence of deep venous thrombosis (DVT).

METHODS

A total of 231 patients with DVT who met the study criteria and whose data could be accessed were enrolled to this retrospective single-centered cross-sectional study. Of them 26 patients with DVT recurrence consisted of the study group (Group 1) while remaining 205 cases without recurrence were considered as the control population (Group 2). The patients' basic clinical features and laboratory results from the complete blood count (CBC) test were recorded and compared between groups. Following univariate analyses, a multivariate logistic regression analysis was performed to identify the independent predictors of the recurrence of DVT. Additionally, a receiver-operating characteristic (ROC) curve analysis was performed to detect the cut-off values of the predictors with sensitivity and specificity rates.

RESULTS

There were no significant differences between the groups for basic clinical features, except for diabetes mellitus, pulmonary embolism, and atrial fibrillation. Although the univariate analysis revealed that the median values of NLR, PLR, and SII were significantly higher in the DVT recurrence group, only SII was determined to be a significant and independent predictor of DVT recurrence in the multivariate logistic regression analysis. According to ROC curve analysis, SII of 1685 × 103/mm3 constituted the cut-off value for predicting DVT recurrence with 61.5% sensitivity and 76.6% specificity (AUC = 0.686, p = .001).

CONCLUSION

The present study demonstrated for the first time in the literature that SII significantly predicted the recurrence of DVT.

A systematic review and meta-analysis of risk prediction models for post-thrombotic syndrome in patients with deep vein thrombosis

Objective

This systematic review and meta-analysis aimed to systematically evaluate the prediction models for the risk of post-thrombotic syndrome (PTS) in deep vein thrombosis (DVT) patients.

Methods

This systematic review and meta-analysis was guided by the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). A systematic search on the following electronic database: PubMed/MEDLINE, EMBASE, and Cochrane Library, and Chinese databases such as WANFANG and CNKI was conducted to look for relevant articles based on the research question. The risk of bias for each studies included was carried out based on Prediction Model Risk of Bias Assessment Tool (PROBAST).

Results

We identified 10 studies that developed a total of 13 clinical prediction models for PTS risk in DVT patients, 3 models were externally validated, 2 models were temporally validated. The top 5 predictors were: BMI (N = 9), Varicose vein (N = 6), Baseline Villalta Score (N = 6), Iliofemoral thrombosis (N = 5), and Age (N = 4). The high risk of bias was from the analysis domain, which the number of participants and selection of predictors often did not meet the requirements of PROBAST. A random-effects meta-analysis of C-statistics was conducted, the pooled discrimination was C-statistic 0.75, 95%CI (0.69, 0.81).

Conclusion

Among the 13 PTS risk prediction models reported in this study, no prediction model has been applied to clinical practice due to the lack of external validation. In the development of prediction models, most models were not standardized in data analysis. It is recommended that future studies on the design and implementation of prediction models refer to Transparent reporting of a multivariable prediction model for individual prognosis or diagnosis (TRIPOD) and PROBAST.

Biomarkers and the post-thrombotic syndrome: A systematic review of biomarkers associated with the occurrence of the post-thrombotic syndrome after lower extremity deep venous thrombosis

INTRODUCTION

Post-thrombotic syndrome (PTS) is a frequent chronic complication of deep venous thrombosis (DVT). Biomarkers are potentially valuable clinical tools for handling PTS. The purpose of this review was to examine which biomarkers are associated with the development of PTS in adults with lower extremity DVT.

METHODS

We performed a systematic review of all English language prospective studies of biomarkers and PTS published in PubMed and EMBASE. Studies were included if diagnosing DVT by diagnostic imaging and assessing PTS by clinical scales, for example, the Villalta scale. Biomarkers of thrombophilia and pathological clot properties were not assessed. Data was reported qualitatively.

RESULTS

15 prospective studies were included. Studies varied widely in study design and methods of data analysis. Forty-six different biomarkers were examined, with seven being measured in two or more studies. The most frequently studied biomarkers were D-dimer, CRP, and IL-6. Associations between PTS and D-dimer were predominantly significant, while results on CRP and IL-6 were inconsistent. ICAM-1 was consistently associated with PTS in all studies and at all timepoints. IL-10 was significantly related to PTS development in the largest study and at all time points. Adiponectin, tPA, HRG and TAFI, MMP-1 and -8, and TIMP-1 and -2 were significantly associated with PTS in single studies.

CONCLUSION

(1) Further research on biomarkers and PTS is clearly warranted. (2) Significant differences in study designs made it difficult to draw reliable conclusions regarding individual biomarkers. We suggest the implementation of a standardized framework for the study of biomarkers and PTS, to make comparison of future studies more feasible. (3) D-dimer, ICAM-1, IL-10, MMP-1 and 8, TIMP-1, TIMP-2, and adiponectin are clinical biomarkers of particular interest to include in future studies of PTS. Large scale systemic quantitative proteomic analyses of DVT patients could help identify novel biomarkers of interest in PTS-patients.

Inflammasome Signaling, Thromboinflammation, and Venous Thromboembolism

Venous thromboembolism (VTE) remains a major health burden despite anticoagulation advances, suggesting incomplete management of pathogenic mechanisms. The NLRP3 (NACHT-, LRR- and pyrin domain-containing protein 3) inflammasome, interleukin (IL)-1, and pyroptosis are emerging contributors to the inflammatory pathogenesis of VTE. Inflammasome pathway activation occurs in patients with VTE. In preclinical models, inflammasome signaling blockade reduces venous thrombogenesis and vascular injury, suggesting that this therapeutic approach may potentially maximize anticoagulation benefits, protecting from VTE occurrence, recurrence, and ensuing post-thrombotic syndrome. The nonselective NLRP3 inhibitor colchicine and the anti-IL-1β agent canakinumab reduce atherothrombosis without increasing bleeding. Rosuvastatin reduces primary venous thrombotic events at least in part through lipid-lowering independent mechanisms, paving the way to targeted anti-inflammatory strategies in VTE. This review outlines recent preclinical and clinical evidence supporting a role for inflammasome pathway activation in venous thrombosis, and discusses the, yet unexplored, therapeutic potential of modulating inflammasome signaling to prevent and manage VTE.

Depleted miR-125a-5p Causes Vascular Endothelial Cell Dysfunction in Deep Vein Thrombosis by Targeting Angiopoietin 2

Deep vein thrombosis (DVT) is a common and fatal disease with a pathology involving endothelial dysfunction. The present research aimed to address the potential clinical significance of miR-125a-5p in DVT and its effect on the dysfunction of Human umbilical vein endothelial cells (HUVECs). Serum miR-125a-5p levels were measured using RT-qPCR in 88 patients with DVT and 76 healthy controls. ROC was plotted to evaluate the diagnostic potential of miR-125a-5p. Spearman's correlation coefficient was performed to calculate the correlation between miR-125a-5p and clinical indicators. CCK-8, Transwell, and ELISA were employed to verify the effects of cell proliferation, migration, and inflammatory and adhesion molecules. Dual-luciferase reporter assay to analyze potential target for miR-125a-5p. Serum miR-125a-5p was reduced in patients with DVT compared with healthy controls (P < 0.001). ROC showed that miR-125a-5p significantly identified patients with DVT from the healthy controls (AUC = 0.834). Furthermore, serum miR-125a-5p was negatively correlated with inflammatory factors and coagulation factors. In in vitro studies, proliferation and migration of HUVECs were inhibited by suppressed miR-125a-5p, whereas inflammation and adhesion factors were considerably promoted (P < 0.05). Moreover, miR-125-5p directly targeted the 3'UTR of angiopoietin 2 (ANGPT2) and was negatively regulated. Finally, serum ANGPT2 was elevated in patients with DVT and was negatively correlated with serum miR-125a-5p. The current research demonstrated that decreased miR-125a-5p was a novel potential diagnostic biomarker for DVT and that it may be involved in DVT progression by targeting ANGPT2 to regulate endothelial dysfunction.

Overall Hemostatic Potential Assay Detects Risk of Progression to Post-Thrombotic Syndrome in Anticoagulated Patients following Deep Vein Thrombosis

Deep vein thrombosis (DVT) frequently leads to post-thrombotic syndrome (PTS) which is challenging to predict and prevent. Identifying those at high risk of developing PTS may help to focus preventative strategies. Adults were recruited within 3 months of DVT diagnosis. Blood was sampled during the therapeutic anticoagulation phase. Overall hemostatic potential (OHP) assay, a spectrophotometric assay, was performed on platelet-poor plasma (PPP). In this assay, fibrin formation is triggered by small amounts of thrombin and termed the overall coagulation potential (OCP). Simultaneously, thrombin and tissue plasminogen activator are added to PPP and the resulting fibrin aggregation curve is the overall hemostatic potential (OHP). Fibrinolysis is expressed by the parameter overall fibrinolytic potential (OFP%). Patients were followed up at regular intervals. PTS was diagnosed if the Villalta score was ≥5 at least 3 months after the DVT diagnosis. Results were obtained from 190 patients (53.7% male, mean age 56.9 years). PTS developed in 62 (32.6%) patients. Patients with PTS displayed significantly higher median OCP (45.8 vs. 38.8 units, p = 0.010), OHP (12.8 vs. 9.2 units, p = 0.005) and significantly lower OFP (74.1 vs. 75.6%, p = 0.050). PTS patients had higher neutrophil/lymphocyte ratios (NLR) (2.3 vs. 1.9, p = 0.007). After multivariate analysis, proximal DVT location, history of varicose veins, NLR ≥ 2.6, OHP > 13.0 units and weight >108 kg were independent predictors for PTS. The c-statistic of the multivariate model was 0.77. This pilot study suggests that OHP testing while patients are still anticoagulated may assist in the prediction of PTS development and could assist in prognostication and targeting of preventative measures. However, larger prospective studies are needed to confirm these findings.

Markers of neutrophil activation and neutrophil extracellular traps in diagnosing patients with acute venous thromboembolism: A feasibility study based on two VTE cohorts

Background

Venous thromboembolism (VTE) diagnosis would greatly benefit from the identification of novel biomarkers to complement D-dimer, a marker limited by low specificity. Neutrophil extracellular traps (NETs) have been shown to promote thrombosis and could hypothetically be used for diagnosis of acute VTE.

Objectives

To assess the levels of specific markers of neutrophil activation and NETs and compare their diagnostic accuracy to D-dimer.

Methods

We measured plasma levels of neutrophil activation marker neutrophil elastase (NE), the NET marker nucleosomal citrullinated histone H3 (H3Cit-DNA) and cell-free DNA in patients (n = 294) with suspected VTE (pulmonary embolism and deep vein thrombosis) as well as healthy controls (n = 30). A total of 112 VTE positive and 182 VTE negative patients from two prospective cohort studies were included.

Results

Higher levels of H3Cit-DNA and NE, but not cell-free DNA, were associated with VTE. Area under receiver operating curves (AUC) were 0.90 and 0.93 for D-dimer, 0.65 and 0.68 for NE and 0.60 and 0.67 for H3Cit-DNA in the respective cohorts. Adding NE and H3Cit-DNA to a D-dimer based risk model did not improve AUC.

Conclusions

Our study demonstrates the presence of neutrophil activation and NET formation in VTE using specific markers. However, the addition of NE or H3Cit-DNA to D-dimer did not improve the discrimination compared to D-dimer alone. This study provides information on the feasibility of using markers of NETs as diagnostic tools in acute VTE. Based on our findings, we believe the potential of these markers are limited in this setting.

The Relevance of Anti-PF4 Antibody Isotypes and Endogenous Glycosaminoglycans and their Relationship with Inflammatory Biomarkers in Pulmonary Embolism Patients

Introduction

Previous studies have shown that inflammation may contribute to the interplay of endogenous glycosaminoglycans (GAGs) and anti-PF4 antibodies. In this study, we quantified the levels of anti-PF4 antibody isotypes and endogenous GAGs together with inflammatory biomarkers in pulmonary embolism (PE) patients to determine whether there is a relationship in between. Identification of this relationship may provide insight to the complex pathophysiology of PE and HIT and may also be useful for development of potential prognostic, diagnostic and therapeutic interventions.

Materials and Methods

Plasma samples from PE patients (n: 210) were analyzed for anti-PF4 antibody isotypes and various thrombo-inflammatory cytokines utilizing commercially available biochip array and ELISA methods. The endogenous GAG levels in PE patients’ plasma were quantified using a fluorescence quenching method. The collected data analyzed to demonstrate the relationship between various parameters.

Results

The endogenous GAG levels were increased in the PE group (P < .05). The levels of anti-PF4 antibody isotypes were higher in varying levels in comparison to the normal group (P < .05). Inflammatory cytokines have shown varying levels of increase with IL-6, IL-8 and IL-10 showing the most pronounced values. Mortality outcome was related to increased GAGs and some of the cytokines.

Conclusion

In this study, we demonstrated increased levels of anti-PF4 antibody isotypes, endogenous GAGs, and inflammatory biomarkers in a large patient cohort in PE. The levels of the endogenous GAGs and inflammatory biomarkers were associated with PE severity and mortality. More studies are needed to understand this complex pathophysiology.

Targeting the NLRP3 inflammasome in cardiovascular diseases

The NACHT, leucine-rich repeat (LRR), and pyrin domain (PYD)-containing protein 3 (NLRP3) inflammasome is an intracellular sensing protein complex that plays a major role in innate immunity. Following tissue injury, activation of the NLRP3 inflammasome results in cytokine production, primarily interleukin(IL)-1β and IL-18, and, eventually, inflammatory cell death - pyroptosis. While a balanced inflammatory response favors damage resolution and tissue healing, excessive NLRP3 activation causes detrimental effects. A key involvement of the NLRP3 inflammasome has been reported across a wide range of cardiovascular diseases (CVDs). Several pharmacological agents selectively targeting the NLRP3 inflammasome system have been developed and tested in animals and early phase human studies with overall promising results. While the NLRP3 inhibitors are in clinical development, multiple randomized trials have demonstrated the safety and efficacy of IL-1 blockade in atherothrombosis, heart failure and recurrent pericarditis. Furthermore, the non-selective NLRP3 inhibitor colchicine has been recently shown to significantly reduce cardiovascular events in patients with chronic coronary disease. In this review, we will outline the mechanisms driving NLRP3 assembly and activation, and discuss the pathogenetic role of the NLRP3 inflammasome in CVDs, providing an overview of the current and future therapeutic approaches targeting the NLRP3 inflammasome.

Predictive Value of Inflammation Biomarkers in Patients with Portal Vein Thrombosis

BACKGROUND AND AIMS

To investigate the usefulness of inflammation biomarkers to serve as a predictors of portal vein thrombosis (PVT) postoperatively (post) in patients with portal hypertension after splenectomy and periesophagogastric devascularization.

METHODS

A total of 177 liver cirrhosis patients were recruited from January 2013 to December 2017. They were divided into a PVT group (n=71) and a non-PVT group (n=106), according to ultrasound examination findings at 7-day post. Inflammation biomarkers involving platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), red blood cell distribution width-to-platelet ratio(RPR), mean platelet volume-to-platelet ratio (MPR) preoperatively (pre) and at 1, 3, 7-days post were recorded.

RESULTS

The univariate logistic regression analysis indicated that PLR (pre) (odds ratio (OR)=3.963, 95% confidence interval (CI)=2.070-7.587, p<0.000), MLR (pre) (OR=2.760, 95% CI=1.386-5.497, p=0.004), PLR (post-day 7) (OR=3.345, 95% CI=1.767-6.332, p=0.000) were significantly associated with the presence of PVT. The multivariate logistic regression analysis results indicated that PLR (pre) (OR=3.037, 95% CI=1.463-6.305, p=0.003), MLR (pre) (OR=2.188, 95% CI=1.003-4.772, p=0.049), PLR(post-day 7) (OR=2.166, 95% CI=1.053-4.454, p=0.036) were independent factors for predicting PVT.

CONCLUSIONS

The PLR (pre), MLR (pre), and PLR (post-day 7) are predictors of portal vein thrombosis post in patients with portal hypertension after splenectomy and periesophagogastric devascularization.

Time-Restricted Salutary Effects of Blood Flow Restoration on Venous Thrombosis and Vein Wall Injury in Mouse and Human Subjects

BACKGROUND

Up to 50% of patients with proximal deep vein thrombosis (DVT) will develop the postthrombotic syndrome characterized by limb swelling and discomfort, hyperpigmentation, skin ulcers, and impaired quality of life. Although catheter-based interventions enabling the restoration of blood flow (RBF) have demonstrated little benefit on postthrombotic syndrome, the impact on the acuity of the thrombus and mechanisms underlying this finding remain obscure. In experimental and clinical studies, we examined whether RBF has a restricted time window for improving DVT resolution.

METHODS

First, experimental stasis DVT was generated in C57/BL6 mice (n=291) by inferior vena cava ligation. To promote RBF, mice underwent mechanical deligation with or without intravenous recombinant tissue plasminogen activator administered 2 days after deligation. RBF was assessed over time by ultrasonography and intravital microscopy. Resected thrombosed inferior vena cava specimens underwent thrombus and vein wall histological and gene expression assays. Next, in a clinical study, we conducted a post hoc analysis of the ATTRACT (Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis) pharmacomechanical catheter-directed thrombolysis (PCDT) trial (NCT00790335) to assess the effects of PCDT on Venous Insufficiency Epidemiological and Economic Study quality-of-life and Villalta scores for specific symptom-onset-to-randomization timeframes.

RESULTS

Mice that developed RBF by day 4, but not later, exhibited reduced day 8 thrombus burden parameters and reduced day 8 vein wall fibrosis and inflammation, compared with controls. In mice without RBF, recombinant tissue plasminogen activator administered at day 4, but not later, reduced day 8 thrombus burden and vein wall fibrosis. It is notable that, in mice already exhibiting RBF by day 4, recombinant tissue plasminogen activator administration did not further reduce thrombus burden or vein wall fibrosis. In the ATTRACT trial, patients receiving PCDT in an intermediate symptom-onset-to-randomization timeframe of 4 to 8 days demonstrated maximal benefits in Venous Insufficiency Epidemiological and Economic Study quality-of-life and Villalta scores (between-group difference=8.41 and 1.68, respectively, P<0.001 versus patients not receiving PCDT). PCDT did not improve postthrombotic syndrome scores for patients having a symptom-onset-to-randomization time of <4 days or >8 days.

CONCLUSIONS

Taken together, these data illustrate that, within a restricted therapeutic window, RBF improves DVT resolution, and PCDT may improve clinical outcomes. Further studies are warranted to examine the value of time-restricted RBF strategies to reduce postthrombotic syndrome in patients with DVT.

Prognostic nomogram for 30-day mortality of deep vein thrombosis patients in intensive care unit

Background

We aimed to use the Medical Information Mart for Intensive Care III database to build a nomogram to identify 30-day mortality risk of deep vein thrombosis (DVT) patients in intensive care unit (ICU).

Methods

Stepwise logistic regression and logistic regression with least absolute shrinkage and selection operator (LASSO) were used to fit two prediction models. Bootstrap method was used to perform internal validation.

Results

We obtained baseline data of 535 DVT patients, 91 (17%) of whom died within 30 days. The discriminations of two new models were better than traditional scores. Compared with simplified acute physiology score II (SAPSII), the predictive abilities of two new models were improved (Net reclassification improvement [NRI] > 0; Integrated discrimination improvement [IDI] > 0; P < 0.05). The Brier scores of two new models in training set were 0.091 and 0.108. After internal validation, corrected area under the curves for two models were 0.850 and 0.830, while corrected Brier scores were 0.108 and 0.114. The more concise model was chosen to make the nomogram.

Conclusions

The nomogram developed by logistic regression with LASSO model can provide an accurate prognosis for DVT patients in ICU.

Imaging inflammation and its resolution in health and disease: current status, clinical needs, challenges, and opportunities

Inflammation is a normal process in our body; acute inflammation acts to suppress infections and support wound healing. Chronic inflammation likely leads to a wide range of diseases, including cancer. Tools to locate and monitor inflammation are critical for developing effective interventions to arrest inflammation and promote its resolution. To identify current clinical needs, challenges, and opportunities in advancing imaging-based evaluations of inflammatory status in patients, the U.S. National Institutes of Health convened a workshop on imaging inflammation and its resolution in health and disease. Clinical speakers described their needs for image-based capabilities that could help determine the extent of inflammatory conditions in patients to guide treatment planning and undertake necessary interventions. The imaging speakers showcased the state-of-the-art in vivo imaging techniques for detecting inflammation in different disease areas. Many imaging capabilities developed for 1 organ or disease can be adapted for other diseases and organs, whereas some have promise for clinical utility within the next 5-10 yr. Several speakers demonstrated that multimodal imaging measurements integrated with serum-based measures could improve in robustness for clinical utility. All speakers agreed that multiple inflammatory measures should be acquired longitudinally to comprehend the dynamics of unresolved inflammation that leads to disease development. They also agreed that the best strategies for accelerating clinical translation of imaging inflammation capabilities are through integration between new imaging techniques and biofluid-based biomarkers of inflammation as well as already established imaging measurements.-Liu, C. H., Abrams, N. D., Carrick, D. M., Chander, P., Dwyer, J., Hamlet, M. R. J., Kindzelski, A. L., PrabhuDas, M., Tsai, S.-Y. A., Vedamony, M. M., Wang, C., Tandon, P. Imaging inflammation and its resolution in health and disease: current status, clinical needs, challenges, and opportunities.

The role of serum bilirubin levels in determining venous thromboembolism

OBJECTIVE

Venous thromboembolism (VTE) is a disease that includes both deep venous thrombosis (DVT) and pulmonary embolism (PE). Bilirubin is an endogenous anti-inflammatory marker associated with atherothrombosis. The purpose of our study was to investigate the association of serum bilirubin levels with the presence of VTE.

METHODS

A total of 103 patients with VTE (distal DVT, n = 34; proximal DVT, n = 30; PE, n = 39) and 50 control patients were cross-sectionally enrolled. Peripheral venous duplex ultrasound and computed tomography were used for the diagnosis of VTE. Fasting blood samples were drawn for biochemical analyses.

RESULTS

Baseline characteristics were not different between groups. The VTE group had lower bilirubin level (9.0 ± 2.6 μmol/L vs 7.3 ± 3 μmol/L; P = .001) and higher high-sensitivity C-reactive protein (hs-CRP) concentration (0.8 [0.3-2] mg/L vs 1.1 [0.2-3] mg/L; P = .008) and white blood cell count (7.4 ± 1.5 × 10⁹/L vs 8.2 ± 2.7 × 10⁹/L; P = .02) compared with control patients. In the analysis of variance, the levels of total direct bilirubin and hs-CRP were clearly different between the control group and VTE subgroups (distal and proximal DVT and PE). The receiver operating characteristic curve analysis showed a cutoff value of 8.9 μmol/L for total bilirubin (sensitivity, 74%; specificity, 55%) and an area under the curve of 0.659 (P < .001).

CONCLUSIONS

Bilirubin level, hs-CRP concentration, and white blood cell count were independently associated with VTE.

Use of Micronized Purified Flavonoid Fraction Together with Rivaroxaban Improves Clinical and Ultrasound Outcomes in Femoropopliteal Venous Thrombosis: Results of a Pilot Clinical Trial

INTRODUCTION

The aim of this study was to assess the impact of adding long-term micronized purified flavonoid fraction (MPFF) to standard treatment of femoropopliteal deep vein thrombosis (DVT).

METHODS

This pilot, comparative, open-label study with blinded outcome assessor enrolled patients with a first episode of femoropopliteal DVT confirmed by duplex ultrasound scanning (DUS). All participants were randomly allocated to one of two treatment groups: (1) control that received a standard treatment with oral rivaroxaban, and (2) experimental that involved additional treatment with MPFF 1000 mg/day. Both drugs were used for 6 months. Patients were followed for the whole treatment period and underwent DUS every 2 months to determine the degree of recanalization by popliteal (PV), femoral vein (FV), and common femoral vein (CFV) compressibility. Thrombi extension were assessed by the modified Marder score. At the end of the follow-up period, patients were assessed with Villalta and venous clinical severity scales (VCSS). Patients with a Villalta score ≥ 5 were diagnosed with post-thrombotic syndrome (PTS).

RESULTS

Sixty patients were randomized to the control or MPFF groups (n = 30 in each group). There were 40 men and 20 women with a mean age ± SD of 56.3 ± 13.4 years. Clinically unprovoked DVT was recognized in 65% of cases and left side localization in 45%. The mean baseline Marder score was 15.0 ± 4.8 and 11.1 ± 4.3 in the experimental and control groups, respectively (p = 0.002). At 6 months, the mean Villalta score in the MPFF group was significantly lower compared with control (2.9 ± 2.7 versus 5.8 ± 3.0; p < 0.0001). PTS was diagnosed in six patients (20%) and 17 patients (57%) in the experimental and control groups respectively (p = 0.007). A significant difference between the groups was also observed for the VCSS value (2.3 ± 1.9 versus 4.9 ± 1.9; p < 0001). After 6 months of treatment the Marder score decreased to 0.8 ± 1.6 and 2.8 ± 3.5 in the experimental and control groups, respectively (p = 0.006). In the MPFF group, there was a greater reduction in the Marder score (p < 0.0001) and more rapid rate of recanalization for the FV (p < 0.0001), with a non-significant trend for the CFV (p = 0.130) and PV (p = 0.204) compared with the control group. Full recanalization of the PV at 6 months was observed in 24 patients (80%) who had received MPFF, and only 17 patients (57%) in the control group (p = 0.095).

CONCLUSION

The addition of MPFF to standard therapy for DVT in the form of oral rivaroxaban can reduce the incidence of PTS at 6 months in patients with proximal DVT and increase the speed of deep vein recanalization.

FUNDING

Les Laboratoires Servier funded the article processing fees, editorial assistance, and open access fee for this manuscript.

Development of a clinical prediction model for the postthrombotic syndrome in a prospective cohort of patients with proximal deep vein thrombosis

Essentials We developed a prediction model for postthrombotic syndrome (PTS) after deep vein thrombosis (DVT). High risk predictors were iliac vein DVT, BMI>35 and moderate-severe Villalta category. Patients with a score ≥4 had an odds ratio of 5.9 (95% CI 2.1-16.6) for PTS. SOX-PTS score may select DVT patients for close monitoring or aggressive strategies to treat DVT.

SUMMARY

Background Postthrombotic syndrome (PTS) is a chronic complication that develops in 20-50% of patients after deep vein thrombosis (DVT). Although individual risk factors for PTS have been characterized, the ability to predict which DVT patients are likely to develop PTS remains limited. Objective To develop a clinical prediction score for PTS in patients with DVT. Methods The derivation cohort consisted of participants in the SOX Trial, a randomized double-blind placebo-controlled trial of elastic compression stockings versus placebo stockings worn for 2 years after DVT to prevent PTS in patients with a first proximal DVT, enrolled in 24 community and tertiary-care hospitals from 2004 to 2010. Multivariable logistic regression analysis of baseline characteristics was performed. The outcome was the occurrence of PTS, diagnosed starting from 6 months or later according to Ginsberg's criteria. Results Seven hundred and sixty-two patients were included in the analysis. The median follow-up was 728 days. The model includes three independent predictors, and has a range of possible scores from 0 to 5. High-risk predictors were: index DVT in the iliac vein; body mass index of ≥ 35 kg m-2 ; and moderate-severe Villalta severity category at DVT diagnosis. As compared with patients with a score of 0, those with a score of ≥ 4 had an odds ratio of 5.9 (95% confidence interval 2.1-16.6) for developing PTS. Conclusions To our knowledge, this is the first clinical prediction score for PTS. We identified three independent predictors that, when combined, predicted PTS risk after a first proximal DVT. The SOX-PTS score requires external validation before it can be considered for clinical use.

Perivascular Perfusion on Contrast-Enhanced Ultrasound (CEUS) Is Associated with Inflammation in Patients with Acute Deep Vein Thrombosis

Background Inflammatory processes of the venous wall in acute deep vein thrombosis (DVT) play a role in thrombus formation and resolution. However, direct evaluation of the perivascular inflammation is currently not feasible. Objective To assess perivascular perfusion in acute proximal DVT using contrast-enhanced ultrasound (CEUS) reflecting perivenous inflammation and its association with systemic inflammatory markers in a single-centre, prospective observational study. Patients/Methods Twenty patients with proximal DVT underwent CEUS imaging in the thrombosed and contralateral popliteal vein at baseline and after 2 weeks and 3 months. Perfusion was quantified by measuring peak enhancement (PE) and wash-in rate (WiR) in a perivenous region after bolus injection of the contrast agent. High-sensitive C-reactive protein (hsCRP) and interleukin-6 (IL-6) were determined at the time of each CEUS imaging. Results PE and WiR were significantly higher in the thrombosed compared with the unaffected leg at baseline (1,007 vs. 34 au and 103 vs. 4 au/s) and 2-week follow-up (903 vs. 35 au and 70 vs. 4 au/s). Compared with baseline, PE and WiR in the thrombosed leg significantly decreased to 217 au and 18 au/s at 3-month follow-up.At baseline, hsCRP and IL-6 were elevated at 20.1 mg/mL and 8.2 pg/mL and decreased significantly to 2.8 mg/mL and 2.6 pg/mL at 2-week follow-up, remaining low after 3 months. There was a weak association between the level of inflammatory markers and the CEUS parameters at baseline on the thrombosed leg. Conclusion Elevated perivascular perfusion assessed by CEUS imaging is associated with the inflammatory response in acute DVT.

Involvement of inflammatory markers in pathogenesis of venous thromboembolism

Inflammation of the venous wall is involved in thrombogenesis, thrombus resolution, wall remodeling and the post-thrombotic syndrome. Different mechanisms are involved in both arterial and venous thrombosis and patients with atherothrombosis hold a higher risk of venous thrombosis. Although inflammation may represent the connection between arterial and venous thrombosis, it is not yet sure if it is the cause or consequence of venous thrombosis. Consequently, the relationships between inflammation markers as indicators of the inflammatory process and clinical venous thromboembolism need to be investigatd. For example, inflammation mediators such as the pro-inflammatory cytokines interleukin 8 (IL-8), IL-6, monocyte chemotactic protein 1 (MCP-1), C Reactive Protein (CRP), vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), matrix metalloproteinases and tumor necrosis factor alpha (TNF alpha) are all involved in thrombogenesis. Studies of venous thromboembolism on animal models proved that there are specific phases of the inflammatory process in venous thromboembolism and thrombus resolution. Knowing the molecular and immunologic mechanisms, identifying and understanding the inflammation markers which are relevant for venous thrombosis, can help to target specific pathways and to develop future therapies of this disease

Impact of Venous Thromboembolism on the Formation and Progression of Carotid Atherosclerosis: The Tromsø Study

Venous thromboembolism (VTE) is associated with increased risk of arterial cardiovascular diseases (CVD), and development of atherosclerosis secondary to VTE may be an intermediate between VTE and CVD. Therefore, we aimed to investigate whether incident VTE was associated with subsequent carotid atherosclerosis formation and progression in a population-based observational study. Subjects attending two or more ultrasound examinations of the right carotid artery, with measurement of total plaque area (TPA), in the Tromsø Study in 1994–1995, 2001–2002, and/or 2007–2008 were eligible. We identified 150 subjects diagnosed with first-lifetime VTE between the initial and follow-up visit, and randomly selected 600 age- and sex-matched subjects without VTE between the visits. Subjects with VTE and carotid plaque(s) at the first visit had 4.1 mm ² (β: 4.13, 95% CI: −1.72 to 9.98) larger change in TPA between the first and second visit compared with subjects without VTE after adjustment for change in high-sensitivity C-reactive protein (hs-CRP) and traditional atherosclerotic risk factors. The association remained after restricting the analyses to VTE events diagnosed in the first half of the time interval between the carotid ultrasounds (β: 4.02, 95% CI: −3.66 to 11.70), supporting that the change in TPA occurred subsequent to the VTE. No association was found between VTE and novel carotid plaque formation. In conclusion, we found a possible association between VTE and atherosclerosis progression in those with already established carotid plaques, but not between VTE and novel plaque formation. The association between VTE and carotid plaque progression was not mediated by low-grade inflammation assessed by hs-CRP.

Role of Bone Marrow Mononuclear Cell Seeding for Nanofiber Vascular Grafts

OBJECTIVE

Electrospinning is a promising technology that provides biodegradable nanofiber scaffolds for cardiovascular tissue engineering. However, success with these materials has been limited, and the optimal combination of scaffold parameters for a tissue-engineered vascular graft (TEVG) remains elusive. The purpose of the present study is to evaluate the effect of bone marrow mononuclear cell (BM-MNC) seeding in electrospun scaffolds to support the rational design of optimized TEVGs.

METHODS

Nanofiber scaffolds were fabricated from co-electrospinning a solution of polyglycolic acid and a solution of poly(ι-lactide-co-ɛ-caprolactone) and characterized with scanning electron microscopy. Platelet activation and cell seeding efficiency were assessed by ATP secretion and DNA assays, respectively. Cell-free and BM-MNC seeded scaffolds were implanted in C57BL/6 mice (n = 15/group) as infrarenal inferior vena cava (IVC) interposition conduits. Animals were followed with serial ultrasonography for 6 months, after which grafts were harvested for evaluation of patency and neotissue formation by histology and immunohistochemistry (n = 10/group) and PCR (n = 5/group) analyses.

RESULTS

BM-MNC seeding of electrospun scaffolds prevented stenosis compared with unseeded scaffolds (seeded: 9/10 patent vs. unseeded: 1/10 patent, p = 0.0003). Seeded vascular grafts demonstrated concentric laminated smooth muscle cells, a confluent endothelial monolayer, and a collagen-rich extracellular matrix. Platelet-derived ATP, a marker of platelet activation, was significantly reduced after incubating thrombin-activated platelets in the presence of seeded scaffolds compared with unseeded scaffolds (p < 0.0001). In addition, reduced macrophage infiltration and a higher M2 macrophage percentage were observed in seeded grafts.

CONCLUSIONS

The beneficial effects of BM-MNC seeding apply to electrospun TEVG scaffolds by attenuating stenosis through the regulation of platelet activation and inflammatory macrophage function, leading to well-organized neotissue formation. BM-MNC seeding is a valuable technique that can be used in the rational design of optimal TEVG scaffolds.

Deconstructing the Tissue Engineered Vascular Graft: Evaluating Scaffold Pre-Wetting, Conditioned Media Incubation, and Determining the Optimal Mononuclear Cell Source

Stenosis limits widespread use of tissue-engineered vascular grafts (TEVGs), and bone marrow mononuclear cell (BM-MNC) seeding attenuates this complication. Yet seeding is a multistep process, and the singular effects of each component are unknown. We investigated which components of the clinical seeding protocol confer graft patency and sought to identify the optimal MNC source. Scaffolds composed of polyglycolic acid and ε-caprolactone/ι-lactic acid underwent conditioned media (CM) incubation (n = 25) and syngeneic BM-MNC (n = 9) or peripheral blood (PB)-MNC (n = 20) seeding. TEVGs were implanted for 2 weeks in the mouse IVC. CM incubation and PB-MNC seeding did not increase graft patency compared to control scaffolds prewet with PBS (n = 10), while BM-MNC seeding reduced stenosis by suppressing inflammation and smooth muscle cell, myofibroblast, and pericyte proliferation. IL-1β, IL-6, and TNFα were elevated in the seeded BM-MNC supernatant. Further, BM-MNC seeding reduced platelet activation in a dose-dependent manner, possibly contributing to TEVG patency.

Diagnostic biomarkers in venous thromboembolic disease

OBJECTIVE

Venous thromboembolism (VTE) is a common disease with serious, often fatal sequelae. The optimal strategy for diagnosis of VTE remains unclear, although considerable progress has been made in this area. Several new biomarkers have showed promise for diagnosis of VTE, and more are under active investigation. We reviewed the literature for studies evaluating these diagnostic biomarkers.

METHODS

We reviewed the English literature between 1990 and 2015, searching for papers evaluating diagnostic performance of biomarkers in VTE.

RESULTS

D-dimer, a fibrin degradation product, has been thoroughly investigated, and performs well in select populations, although it is best as a rule-out test because of its generally low specificity. Soluble P-selectin, a marker of endothelial activation, has shown good diagnostic performance in several studies but has not yet been adopted widely. Others, including cellular adhesion molecules, tissue factor, circulating microparticles, and C-reactive protein, are under investigation, with varying results in a few studies.

CONCLUSIONS

At this time, D-dimer and P-selectin remain the most clinically valuable. New biomarkers are needed for clinical use in VTE.